ingester: fix ctrl-c handler

[fanatid]

The current Ctrl-C handler doesn't make any sense, everything works the same even if we do not have this handler.
Instead of returning JoinHandle from the functions I made them async and used try_join_all with signals (sigterm ,sigint). Right now all tasks actually never return Err but we can change it in the future and signals handler still would work correctly.

fmt, clippy (+rust update) can be moved to another PR, if required

[fanatid]

Need to be updated after #141
Not actuall with nft_ingester2.